Binary To Decimal in C

Posted on October 18, 2011August 21, 2017 by Sandeepa Nadahalli

C Program to convert a binary number into its equivalent Decimal. In binary number system or base-2 system numeric valuer are represented by using two different symbols 0 and 1. The binary number system is a positional notation with a radix of 2.

This program converts a given base-2 number to it’s decimal equivalent (or base-10 representation).

The Program

	#include<stdio.h>

	/*
	* Function to convert a given binary number to
	* its decimal equivalent.
	*/
	int binary_to_decimal(int num) {
	int rem, base = 1, decimal_number = 0;
	while( num > 0) {
	rem = num % 10;
	if((rem == 0) \|\| (rem == 1)) {
	decimal_number = decimal_number + rem * base;
	num = num / 10 ;
	base = base * 2;
	} else {
	return -1; // Invalid binary number
	}
	}
	return decimal_number;
	}

	int main() {
	long int binary_number, decimal_number;
	printf("Enter any binary number : ");

	scanf("%ld", &binary_number);

	decimal_number = binary_to_decimal(binary_number);

	if(decimal_number != -1) {
	printf("The decimal equivalent value of binary %ld is: %ld",
	binary_number, decimal_number);
	} else {
	printf("\nPlease enter a valid binary number!");
	}
	return 0;
	}

view raw binary_to_decimal.c hosted with ❤ by GitHub

Sample Output

Binary To Decimal

Related Programs

Edit1: 21st August 2017

Added links to related programs
Added a screenshot of sample output
Moved program to it’s own gist.

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C program to find the 2’s complement of a binary number.

Posted on October 12, 2011 by Sandeepa Nadahalli

C Program to calculate the 2’s complement of a binary number. 2’s complement of a number is obtained by scanning it from right to left and complementing all the bits after the first appearance of a 1. Thus 2’s complement of 11100 is 00100. Read more about C Programming Language .

/***********************************************************
* You can use all the programs on  www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact [email protected]
* To find more C programs, do visit www.c-program-example.com
* and browse!
* 
*                                  Happy Coding
***********************************************************/


#include <stdio.h>
#include<conio.h>

void complement (char *a);
void main()
{
 char a[16];
 int i;
 clrscr();
 printf("Enter the binary number");
 gets(a);
 for(i=0;a[i]!=''; i++)
 {
  if (a[i]!='0' && a[i]!='1')
  {
   printf("The number entered is not a binary number. Enter the correct number");
   exit(0);
  }
 }
complement(a);
getch();
}
void complement (char *a)
{
 int l, i, c=0;
 char b[16];
 l=strlen(a);
 for (i=l-1; i>=0; i--)
 {
  if (a[i]=='0')
  b[i]='1';
  else
  b[i]='0';
 }
 for(i=l-1; i>=0; i--)
 {
 if(i==l-1)
 {
  if (b[i]=='0')
  b[i]='1';
  else
  {
   b[i]='0';
   c=1;
  }
 }
 else
 {
  if(c==1 && b[i]=='0')
  {
   b[i]='1';
   c=0;
  }
 else if (c==1 && b[i]=='1')
 {
  b[i]='0';
  c=1;
 }
}
}
b[l]='';
printf("The 2's complement is %s", b);
}

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C Program to convert a given decimal number into its binary equivalent

Posted on September 30, 2011August 11, 2017 by Sandeepa Nadahalli

C Program to convert a given decimal number into its binary equivalent. In this program we convert the given decimal based number system(0, 1, 2, 3, —–,9) to Binary number system(0 and 1). Read more about C Programming Language .

	/***********************************************************
	* You can use all the programs on www.c-program-example.com
	* for personal and learning purposes. For permissions to use the
	* programs for commercial purposes,
	* contact [email protected]
	* To find more C programs, do visit www.c-program-example.com
	* and browse!
	*
	* This program was originally published at
	* http://www.c-program-example.com/2011/09/you-can-use-all-programs-on-www_8419.html
	* Happy Coding
	***********************************************************/

	/* Write a program to convert a given decimal numbers into its binary equivalent . */


	#include<stdio.h>
	int main()
	{
	int num,i=0,binary=0,num1, biny[30],counter=0;
	printf("Enter the Decimal number:\n");
	scanf("%d",&num);
	num1=num;
	do
	{
	binary=num%2;
	biny[i]=binary;
	num=num/2;
	i++;
	counter++;
	} while(num>0);

	printf("\nThe given decimal %d number binary equalant is :\n",num1);
	counter--;
	while(counter>=0){
	printf("%d" ,biny[counter]);
	counter--;
	}

	return 0;
	}

view raw decimal_to_binary.c hosted with ❤ by GitHub

C Program Examples

binary numbers